Fan wheel



Sept. 13, 1932. F. J. MCMURDIE FAN WHEEL Filed Aug. 19, 1927 Patented Sept. 13, 1932 UNITED STATES. PATENT OFFICE FRANCIS J. MGMUBDIE, OF KALAMAZOO, MICHIGAN, ASSIGNOR TO CLARAGE FAN COMB IPANY, OF KALAMAZOO, MICHIGAN FAN WHEEL Application filed August 19, 1927. Serial No. 214,079.

Objects relating to details of construction and operation will appear from the detailed description to follow. The invention is defined in the claim. A structure showing a preferred embodiment of my inventionis illustrated in the accompanying drawing, in whch:

Fig. 1 is a central sectional elevation of a I fan embodying the features of my invention,

-; each ring being a cone section.

taken on irregular line 11 of Fig. 2.

'Fig. 2 is an end elevation View from the intake side of the fan, a portion being in section on the irregular section line 22 of I Fig. 1, the position and relation of the blades being indicated by dotted lines on the cutaway portion. 1 V

Fig. 3 is a detail view of one of the developed blades, showing its slitting at the mid portion and projecting tenons at the ends.

Fig. 4: is an enlarged detail partial section-' al view showing the welding at the end of one of the blades, taken on line 44 of Fig. 2.

Fig. 5 is a detail view showing the welding.

of one of the blades to the intermediate rings.

The parts are identified by numerals of reference which are the same in all views.

1 is the cast hub of conical form. 2' is the back plate of the fan wheel suitably flanged at 21. 3 is the front ring forming the intake aperture by the flange 4. 5 are the peripherally disposed fan blades in volute arrangement. 6 and 7 are the intermediate supporting rings, The fan blades 5 are provided with tenons 53, 53 for securing them to the fan back plate 2 and with tenons 54 for securing them to the front ring 3, and are slotted at 51 at their outside margins and at 52 at their inside margins, as seen in Fig. 3. Theintermediate outer ring 6 is disposed in the outer slot 51 and the ring 7 is disposed in the inner slot 52, the rings 6 and 7 being sections of the same cone. They are welded by electric or acetylene intermediate the length of the fan blades,

thus enabling long blades to bereadily installed and also making possible the use of light weight material in the blades. These intermediate rings act very much like tires to hold the blades in position. Iam aware that flat rings have been inserted and secured by rivets. In. such therivets" are expensiveand result in numerous perforations and weakening and also present imperfect surfaces, causing undue friction.

The outer ring 3 of the fan is connected by diagonally-disposed radial brace bolts 8 to the hub, three or more in number, six being here shown, the same being adjustable by the lock v nut 9 at the inner end and by the adjusting lock nuts 10 and 11 at the outer end. The fan Wheel of course is capable of being used in various relations. V p

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is: p

A fan wheel comprising a suitable hub, a circular backplat-e secured thereto, a front fan ring open to form an intake at the center, peripherally-disposed volute fan blades slotted at their mid portions on their outside margins, and on their inside margins, and tenoned into said back'plate and front ring.

and welded at. the tenons,'and intermediate, rings of conical sections disposed in sald slots in each of said blades outside and inside, and

welded at the meeting points of the slots in the blades to the rings whereby the full tensile strength of the rings is preserved with minimum obstruction to air flow, as specified.

In witness whereof I have hereuntof set my hand.

vFRANCIS J. MoMURDIE.- I p I 

